A legislative veto override is a procedure by which Congress can override a presidential veto and enact legislation into law. This power is intended to ensure that the President cannot unilaterally block legislation that has been passed by Congress.

Article I, Section 7 of the U.S. Constitution requires a two-thirds majority vote in both the House of Representatives and the Senate to override a presidential veto.

The procedure for overriding a presidential veto is outlined in Article I, Section 7 of the U.S. Constitution. The House of Representatives must first vote to override the veto by a two-thirds majority. If the House vote is successful, the Senate must then vote to override the veto by a two-thirds majority.

The legislative veto override power was first used in 1811, when Congress overrode President James Madison's veto of a bill to recharter the Bank of the United States. This was a significant event in the history of the U.S. presidency, as it demonstrated that Congress had the power to override a presidential veto.

As of 2023, a presidential veto has been overridden more than 30 times in U.S. history. The most recent override occurred in 2016, when Congress overrode President Barack Obama's veto of a bill to allow families of 9/11 victims to sue the government of Saudi Arabia.

Franklin D. Roosevelt has had the most vetoes overridden, with 9 vetoes being overridden during his presidency.

George Washington has had the fewest vetoes overridden, with 0 vetoes being overridden during his presidency.

The longest period of time that a President has gone without having a veto overridden is 24 years, which occurred between 1845 and 1869.

The shortest period of time that a President has gone between having two vetoes overridden is 1 day, which occurred in 1864 when President Abraham Lincoln had two vetoes overridden on the same day.

Andrew Johnson has had the highest percentage of vetoes overridden, with 15% of his vetoes being overridden.

George Washington has had the lowest percentage of vetoes overridden, with 0% of his vetoes being overridden.

The most common reason for a presidential veto to be overridden is that Congress believes that the veto is harmful to the national interest.

The least common reason for a presidential veto to be overridden is that Congress believes that the veto is unconstitutional.

A legislative veto override weakens the President's power because it demonstrates that Congress is willing to challenge the President's authority.

A legislative veto override strengthens the power of Congress because it demonstrates that Congress is able to assert its authority over the President.